Vacuum pressure control valve



Oct. 22, 1968 H. (3. MAY

VACUUM PRESSURE CONTROL VALVE Original Filed March 26, 1965 6 m h mm 9w8 mm m m f S. Q 5 m" Q 9 1 mm m 9 M m m JINNMJ vm mm Om m mm WW m n N t9 o 3 mm h m m mw 9 e g mv 5 m 9 mm 5 an M 4 wv W on a m K 6 m mn S QW\NO@ n Q no w. 552:6 6 mm mm mm 7 8 8 mm INVENTOR. HARRY C. MAY

ATTORNEY 3,407,008 VACUUM PRESSURE CONTROL VALVE Harry C. May,McKeesport, Pa., assignor to Westinghouse Air Brake Company, Wiimerding,Pa., a corporation of Pennsylvania Original application Mar. 26, 1965,Ser. No. 442,855, now Patent No. 3,272,563, dated Sept. 13, 1966.Divided and this application May 25, 1366, Ser. No. 552,965

Claims. (Cl. 303--12) ABSTRACT 0F THE DISCLOSURE A vacuum pressurecontrol valve device comprising a movable abutment, subject on itsrespective opposite sides to a control fluid pressure and the force of aspring, for actuating a cam device to control the degree of unseating ofa valve from its seat thereby to vary the rate of admission of air atatmospheric pressure into a vacuum pressure control communicationwhereby the degree of sub-atmospheric pressure therein is regulatedaccording to the control fluid pressure.

Background of the invention This application is a division of Patent3,272,563 issued Sept. 13, 1966, to Harry C. May and assigned to theassignee of the present invention. In the aforesaid patent there isdisclosed a multi-unit locomotive exhauster control appaartus, whereineach unit is provided with an exhauster and with a fluid pressureoperated valve device for controlling a communication between therespective exhauster and the vacuum brake pipe on the locomotive unitsand cars, which valve device is operative to regulate the vacuumpressure or degree of sub-atmospheric pressure supplied from therespective exhauster to the vacuum train brake pipe. The specificfeatures of this fluid pressure operated vacuum pressure control valvedevice constitute the present invention.

More specifically, the present invention comprises a novel vacuumpressure control valve device comprising a movable abutment, subject onits respective opposite sides to a control fluid pressure and the forceof a spring, for actuating a cam device to control the degree ofunseating of a valve from its seat thereby to vary the rate of admissionof air at atmospheric pressure into a vacuum pressure controlcommunication, such as, for example, a vacuum brake pipe on a train ofcars, whereby the vacuum pressure or degree of sub-atmospheric pressuretherein is regulated according to the control fluid pressure which, forexample, may be the pressure in a brake pipe extending from end to endof a multi-unit locomotive.

In the accompanying drawing, the single figure is a schematic view,partly in section, showing the present invention.

Description As shown in the drawing, the degree of sub-atmosphericpressure or vacuum in a pipe 1, which may be, for example, a trainvacuum brake pipe, is controlled by a fluid pressure operated valvedevice 2 which is connected to the pipe 1 by a pipe 3 and to a vacuumreservoir 4 by a pipe 5. In order that fluid may be evacuated from thevacuum reservoir 4 to establish a sub-atmospheric pressure therein andalso in the vacuum brake pipe 1, the reservoir 4 is connected to anexhauster device by a pipe 6.

To provide for the operation of the valve device 2 according to thedegree of a control fluid pressure, this valve device is connected tothe outlet or delivery port of any nited States Patent 0" 3,407,0fl8Patented Oct. 22, 1968 suitable manually operated self-lapping valvedevice 7 by a pipe 8. This manually operated self-lapping valve device 7is provided with a supply port which is connected by a pipe 9 to areservoir 10 which may be charged with fluid under pressure from a fluidcompressor (not shown) via a pipe 11.

The fluid pressure operated valve device 2 comprises a casing 12 betweenthe left-hand end of which end a cover member 13 is clamped the outerperiphery of a movable abutment or diaphragm 14 which, in cooperationwith the cover member 13, forms on one side of the diaphragm a controlchamber 15. The control chamber 15 is connected to the self-lappingvalve device 7 via the hereinbefore-mentioned pipe 8 and acorrespondingly numbered passageway extending through the cover member13 and the casing 12. The inner edge of the diaphragm 14 is clampedbetween a diaphragm follower 16 and an annular diaphragm follower plate17 through which extends a screw-threaded stem 18 that is formedintegral with the diaphragm follower 16 and which receives a nut 19 forforcing the follower plate 17 against the follower 16.

Formed integral with the right-hand side of the diaphragm follower 16 isan operating stem 20 that extends through a bore 21 in a boss 22 that isintegral with the upper wall of the casing 12 and extends downwardtherefrom into a chamber 23 within the casing. The chamber 23 is open toatmosphere through an insect excluder device 24 carried by a bottomcover 25 that is secured to the bottom wall of the casing 12 by anysuitable means (not shown) to close an opening 26 in this bottom wall.Disposed in the chamber 23 coaxial with the operating stem- 20 is a camcarrier 27 that is supported by a pair of spaced-apart identical rollers28 which are respectively rotatably mounted on a pair of parallelspacedapart shafts 29 and 30 that have their respective opposite endsanchored in the opposite vertical walls of the casing 12.

The cam carrier 27 is rectangular in shape and has a recess 31 formed inits upper face, as by a milling operation. The width of the recess 31 isless than the width of the cam carrier 27 so that the milling operationforms two upstanding parallel spaced-apart walls in which are anchoredthe opposite ends of a pin 32 on which is pivotally mounted adjacent oneend thereof a cam element 33. Extending through the cam carrier 27 andopening into the recess 31 is a bore 34 into which is press-fitted abushing 35 that has a screw-threaded bore in which is carried anadjusting screw 36 that supports the left-hand end of the cam element33. Disposed above the cam element 33 is a cam lever 37 which ispivotally mounted adjacent its right-hand end on a pin 38 that has itsopposite ends anchored in the opposite vertical walls of the casing 12.The cam lever 37 is also rectangular in shape and has a recess 39 formedin its lower face which extends inward from its lefthand end andterminates adjacent the pin 38 on which the cam lever is pivotallymounted. The width of the recess 39 is less than the width of the camlever 37 so that when the recess 39 is formed in the cam lever 37, as bya milling operation, the cam lever will be provided with two downwardlyextending parallel spacedapart walls in which are anchored in theopposite ends of a first pin 40 on which is rotatably mounted a roller41 that is adapted to roll along a cam surface 42 formed on the camelement 33 as this cam element is moved in either a right-hand or aleft-hand direction from the position in which it is shown in thedrawing, in a manner hereinafter described in detail.

The cam lever 37 is provided with a short slot 43 which extends inwardfrom the left-hand end thereof, the width of which is substantially thesame as the 3. 7 distance between the two downwardly extending parallelspaced-apart walls at the opposite sides of the recess 39. Anchored inthese two'downwardly extended walls at a location that is substantiallymidway the length of the slot 43 is a second pin 44 on which isrotatably mounted a roller'45 upon which rests the lower end of a pushersleeve 46 that extends through a bore 47 formed in a boss 48 that isintegral with the upper-wall" of the casing 12-and extends downtherefrom into the chamber 23.

The pusher sleeve 46 is provided with a bottom bore 49 and a coaxialcounterbore 50 that extends inward from the upper end thereof, whichupper endis disposed in a chamber 51 that is formed in a valve body orhousing 52 that is secured by any suitable meanstnot shown) to anexterior flat surface 53 formed on the upper wall of the casing 12.Slidably mounted in the bottom bore 49 is the lower end of a valvepusher 54 that has a collar 55 formed at the upper end thereof anddisposed in the countenbore 50. interposed between the collar 55 and thebottom of the counterbore and in surrounding relation to the valvepusher 54 is a spring 56 that is effective to normally bias the collaragainst a snap ring 57 that is inserted in a groove formed in the wallof the counterbore 50 adjacent the upper end thereof.

The upper end of the valve pusher 54 is provided with a headed wear pin58 the head of which abuts a corresponding head formed at the lower endof a valve tip 59 that is carried by a poppet-type valve 60 having afluted stem 61 that is disposed in a bore 62 formed in the valve housing52 and extending between the chamber 51 and a chamber 63 formed in theupper end of the valve housing 52.

Disposed in the chamber 63 and interposed between the valve housing 52and the upper end of the fluted stem 61 is a spring 64 that is effectiveto bias the valve tip 59 into contact with the head of the headed pin 58and the valve 60 in a direciton away from an annular valve seat 65formed at the lower end of the bore 62.

Opening into the chamber 63 is one end of a passageway 66 the oppositeend of which is connected by a pipe bearing the same numeral to theoutlet of an atmospheric air filter device 67 to the inlet of which isconnected one end of a pipe 68 the opposite end of which is open toatmosphere. While the valve 60 is held unseated by the spring 64, thefilter device 67 serves to remove contaminants from atmospheric airadmitted to the chamber 51 into which opens one end of the pipe 5 andalso one end of the pipe 3 that has its opposite end connected to thevacuum brake pipe 1.

The upper wall of the casing 12 has formed integral therewith a secondboss 69 that extends downward therefrom, which boss is provided with abore 70 that is coaxial with the bore 21 in the boss 22. Slidablymounted in the bore 70 is a carriage pusher 71 one end'of which abutsthe right-hand end of the cam carrier 27 and the opposite end of whichis secured to a spring seat 72.

A heavy spring :73 is interposed between the spring seat which areanchored in the opposite vertical walls of the stationary casing 12, thecover member 13 is provided with a bore 77 into the right-hand end ofwhich is pressfitted a bushing 78 having intermediate its ends of collar79 which rests against the'cover member 13 at the righthand end of thebore 77. v

The bushing 78 is provided with a central internally screw-threaded bore80 for receiving an adjusting screw 81 the right-hand end of which abutsthe left-hand end of the screw-threaded stem 18 that is integral withthe diaphragm follower 16. Intermediate its ends the screwthreaded bore80 is provided with an internal annular groove in which is ins' erted anO-ring' 82 that forms a seal with'the' adjusting screw 81 to preventleakage of fluid} under pressure from the control chamber 15along theadjusting screw 81 to a chamber '83 formed by the cooperativerelationship of the bushing 78, the wall of the bore 77 and acylindrical head 84 formed integral with the adjusting screw 81. Thecylindrical head 84 is provided with a peripheral'annular groove intowhich is inserted an O-ring 85 that forms a seal with the wall surfaceof the bore 77 to prevent leakage of the fluid under pressure from thechamber 83 to atmosphere.

The cylindrical head 84 is further provided with a screw-driver slot 86for receiving the end of a screwdriver the rotation of which in onedirection is effective to move the cam carrier 27 and cam element 33 viathe stems 18 and 20 that are integral with the'diaphragm follower 16 inthe direction of the right-hand against the yielding resistance of theheavy spring 73 until a reference mark (not shown) formed on the camelement 33 is in alignment with a corresponding reference mark (notshown) formed on the cam lever 37. It will be understood from theforegoing that rotation of the screwdriver in the opposite direction sothat the adjusting screw 81 ismoved away from the screw-threaded stem 18renders .the heavy spring 73 effective to move the cam carrier 27 andcam element 33 via the carriage pusher 71 in the direction of theleft-hand so that the left-hand end of the stem 18, is maintained incontact with the righthand end of the adjusting screw 81. Thus, if wheninitially assembled, the reference mark formed on the cam element 33 iseither on the left-hand side. or on the righthand side of the referencemark on the cam lever 37, the cam carrier 27 and cam element 33 carriedthereby can be moved in the proper direction to bring the reference markon the cam element 33 into alignment with the corresponding referencemark on the cam lever 37.

It should be noted at this time that the number of shims 74 disposedbetween the right-hand end of the heavy spring .73 and the cover member76 must be such that, when the cam carrier 27 is adjusted to theposition in which the reference mark on the cam element 33 carriedthereby is in alignment with the reference markon the cam lever 37 thecompressed value of the heavy spring 73 is equal to the effective areaof the diaphragm 14 in square inches multiplied by fifty poundspersquare inch, since it is desired that the fluid pressure operatedvacuum control valve device 2 controls variations in the subatmosphericpressure in the vacuum brake pipe 1 from zero inches of mercury(atmospheric pressure) to- 20 inches of mercury accordingly as thepressurein the pipe 8 and chamber 15 is varied from fifty pounds persquare inch to seyenty pounds per square inch, it being understood thatwhile the diaphragm 14, cam carrier 27, and cam lever 37 occupy theposition shown in the drawing, the valve 60 is biased away fromtheannular valve seat 65 by the spring 64 to. its fully opened positionso that atmospheric air admitted through the filter device 67 willincrease the subatmospheric pressure in the vacuum brake pipe 1 toatmospheric pressure. I

The valve device 7 is a self-lapping type of valve device, havingtaself-lapping unit of any-well-k-nown construction which, while .a -valve,operating handle 87 occupies a maximum pressure position, will beactuated to supply fluid under pressure from the reservoir 10 that isconnected; to the valvedevice 7 by the pipe 9, to the pipe 8 which isconnectedtothe chamber 15 so thatthe fluid under pressure .thus suppliedto the pipe-8 and the chamber. 15 increases the pressure therein to apreselected normal charge value. I

The valve-device 7 has a. pressure reduction zone that extends betweenits maximum pressure position and a minimum reduced pressure position sothat as an operator moves the handle 87 arcuately from its maximumpressure position into its pressure reduction zone an extentcorresponding to the degree of pressure desired in the pipe 8 andchamber 15, fluid under pressure will be exhausted from the pipe 8 andchamber 15 proportional to the amount of arcuate movement of the handle87 into this zone, thus providing a graduated reduction of pressure inthe chamber 15.

Operation Assume initially that the reservoir 10 is charged with fluidto a chosen pressure such as, for example, one hundred pounds per squareinch, that handle 87 of the manually operative self-lapping valve device7 is in its maximum pressure position; that the self-lapping unit of thevalve device 7 has been adjusted to provide via pipe and correspondingpassageway 8 a desired normal charged pressure in the chamber of thefluid pressure operated valve device 2 which normal charged pressure maybe, for example, seventy pounds per square inch; and that the exhausteris operating to provide a chosen subat mospheric pressure in the vacuumreservoir 4, the chamber 51 in the fluid pressure operated valve device2, and the vacuum pipe 1 which chosen sub-atmospheric pressure may be,for example twenty inches of mercury (Hg). It should be understood thatwhen the above-mentioned desired normal pressure is present in thechamber 15 of the fluid pressure operated valve device 2, the valve 60of this valve device occupies its minimum open position to allow aminimum rate of flow of air from atmosphere to the chamber 51 via thepipe 68, filter device 67, pipe and passageway 66, chamber 63 and bore62, and thence from chamber 51 to the vacuum pipe 1 via the pipe 3, andto the vacuum reservoir via the pipe 5.

Let it now be supposed that an operator desires to increase thesub-atmospheric pressure in the vacuum pipe 1 to a desired highersub-atmospheric pressure. To do so, he will manually move the handle 87of the self-lapping valve device 7 arcuately from its maximum pressureposition into its pressure reduction zone to an extent corresponding tothe desired degree of increase in the subatmospheric pressure in thevacuum pipe 1. When the handle 87 is moved into its pressure reductionzone, the self-lapping unit of the valve device 7 i is operated to ventfluid under pressure from the pipe 8 and correspondingly from passageway8 and the chamber 15 to cause a reduction of pressure in the chamber 15.

The reduction of the pressure in the chamber 15 of the fluid pressureoperated valve device 2 renders the spring 73 effective, via thecarriage pusher 71, to shift the cam carrier 27 and cam element 33'pivotally mounted thereon in the direction of the left-hand, it beingunderstood that the cam carrier 27 is supported by the rollers 28 sothat the left-hand end of the cam carrier 27 remains in abutting contactwith the righthand end of the operating stem to thereby shift this stemand the diaphragm follower 16 in the direction of the left-hand.

As the cam carrier 27 and the cam element 33 are thus shifted in thedirection of the left-hand, spring 64 is rendered effective to move thevalve 60 downward away from the valve seat 65 so that an increasedquantity of air from the atmosphere flows to the chamber 51 via the pipe68, filter device 67, pipe and corresponding passageway 66, chamber 63,along the fluted stem 61 of the valve 60 and past this unseated valve.As the valve 60 is thus moved downward by the spring 64, it is effectivevia the valve tip 59, wear pin 58, valve pusher 54, spring 56, pushersleeve 46, roller 45, pin 44, and cam lever 37 to maintain the roller4-1 rotatably mounted on the pin 40 that is supported by the cam lever37 in contact with the cam surface 42 on the cam element 33 so that theroller 41 rides down the cam surface 42 as the cam element 33 and camcarrier 27 are moved in the direction of the left-hand by the spring 73until the reduced pressure in the chamber 15 and acting on the effectivearea of the diaphragm 14 balances the force of the spring 73.

As the valve 60 is moved downward away from the valve seat 65, thefiltered air from the atmosphere thus admitted to the chamber 51 flowsto the vacuum brake pipe 1 via the passageway and corresponding pipe 3.

Furthermore, as the valve 60 of the fluid pressure operated valve device2 moves away from the valve seat to increase the degree of opening ofthis valve in response to the reduction of pressure in the chamber 15resulting from the operator moving the handle 87 of the valve device 7to a position in its pressure reduction zone corresponding to thedesired degree of increase in the sub-atmospheric pressure in thevacuumpipe 1, more air from the atmosphere is admitted past the valve 60 perunit of time or per second, but the amount of air from the atmosphereflowing past the valve 60 decreases as the sub-atmospheric pressure inthe vacuum pipe 1 increases. When the sub-atmospher-ic pressure in thevacuum pipe 1 is increased to a value corresponding to the reduction inpressure effected in the chamber 15 of the fluid pressure operated valvedevice 2, the quantity of air flowing from the atmosphere past the valve60 is equal to the quantity of air from the atmosphere that will beevacuated or exhausted by the exhauster. Therefore, the exhausteroperates to evacuate or exhaust all of the air from the atmosphere thatflows past the valve 6% to the chamber 51 in the fluid pressure operatedvalve device 2. Consequently, there will be no further increase in thesub-atmospheric pressure in the vacuum pipe 1.

It will be understood, of course, that the operator may move the handle87 of the self-lapping valve device 7 arcuately to any position in itspressure reduction zone between its maxi-mum pressure position and itsminimum reduced pressure position to cause the valve 60- of the fluidpressure operated device 2 to be moved to a corresponding position withrespect to its seat 65 whereupon the rate of flow of air from theatmosphere to the chamber 51 thus established by the valve 60 effectsthe establishment of a corresponding degree of sub-atmospheric pressurein the vacuum brake pipe 1. Therefore, as the handle 87 is moved fromits maximum pressure position through its pressure reduction zone to itsminimum reduced pressure position, the pressure in the chamber 15 of thevalve device 2 is varied from a chosen maximum pressure, which, forexample, may be seventy pounds per square inch, to a chosen minimumpressure, which, for example, may be fifty pounds per square inch. Inconsequence, the sub-atmospheric pressure in the vacuum pipe 1 iscorrespondingly varied from a chosen minimum sub-atmospheric pressure,which may be, for example, a high degree of vacuum of twenty inches ofmercury (Hg), to atmospheric pressure or no degree of vacuum.

Having now described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. In combination:

(a) a vacuum pipe,

(b) an exhauster and a storage reservoir evacuated thereby,

(c) a communication extending between the storage reservoir and saidvacuum pipe,

(d) a constantly open fluid pressure operated valve means disposed insaid communication and operable in response to variations of a controlfluid pressure for controlling evacuation of fluid under pressure fromsaid vacuum pipe in response to evacuation of the storage reservoir byoperation of said exhauster, said valve means being also operable tovary the amount of fluid admitted from the atmosphere to said vacuumpipe from a chosen maximum to a chosen minimum greater than zeroaccordingly as said control fluid pressure increases from a chosenminimum pressure to a chosen maximum pressure,

(e) a source of fluid under pressure, and

(f) a manually operable valve device for controlling the supply of fluidunder pressure from said source to said fluid pressure operated valvemeans to effect the establishment thereon of said control fluid pressureand for controlling the release of said control fluid pressure toatmosphere to effect a reduction thereof.

2. The combinatiomas claimed in claim 1, further characterized in thatsaid manually operable valve device is of the self-lapping type.

3. In combination:

(a) an exhauster and a reservoir evacuated thereby,

(b) apipe,

(c) a valve device having:

(i) a casing having two coaxially related chambers therein with ashoulder therebetween, one of said chambers being constantly open toatmosphere and the other chamber communicating with said reservoir andsaid pipe,

(ii) an annular valve seat formed on said shoulder,

.(iii) a poppet valve cooperating with said valve seat and movable inthe saidother chamber with respect thereto to vary the clearance betweensaid valve and said valve seat from a chosen maximum to a chosen minimumgreater than zero to vary the rate of admission of air at atmosphericpressure from said one chamber to said other chamber, and

(iv) fluid pressure controlled means for varying the position of saidvalve with respect to said valve seat,

(d) a source of fluid under pressure, and

(e) valve means for controlling the supply of fluid pressure from saidsource to said fluid pressure controlled means.

4. The combination recited in claim 3, further characterized in thatsaid poppet valve is unseated from said valve seat a minimum distanceresponsively to establishment of a maximum fluid pressure on the fluidpressure controlled means and is unseated from said valve seat a maximumdistance responsively to establishment of a minimum fluid pressure onthe fluid pressure controlled means.

5. A fluid pressure operated valve device comprising:

(a) a casing having a first and a second chamber formed therein andconnected by a passageway,

(b) an annular valve seat formed at one end of said passageway, I

(c) a valve operable toward and away from said seat to vary the rate offlow of fluid under pressure from said first chamber to said secondchamber,

(d) a lever pivoted at One end on said casing and operatively connectedat its opposite end to said valve,

(e) a roller carried by said lever intermediate the ends of said lever,

(f) a longitudinally movable carriage member,

(g) a cam pivotally mounted on said carriage member and having a camsurface in contact with said roller,

(h) a spring yieldingly resisting movement in one direction of saidcarriage member, and

(i) a movable abutment .operably connected to said carriage member foreffecting movement thereof against the'yielding resistance of saidspring in response to the supply of fluid under pressure to one side ofsaid abutment to cause movement of said valve toward'said annular valveseat,

(j) the contour of said cam surface being such as to impart movement ofsaid valve toward said annular valve seat to provide a selected rate offlow of fluid under pressure past said valve as the pressure of fluidactive on said one side of said abutment varies from a chosen minimum toa chosen maximum.

6. A fluid pressure operated valve device, as claimed in claim 5,further characterized by means for manually adjusting said cam todifferent fixed positions with respect to said carriage member therebyto correspondingly vary the movement of said valve toward and away fromsaid annular valve seat responsively to movement of said abutment.

7. A fluid pressure operatedv valve device, as claimed in claim 5,further characterized by manually operated means for effectinglongitudinal movement of said carriage member and cam pivotally mountedthereontwith respect to said roller.

8. A fluid pressure operated valve device, as claimed in claim 5,further characterized by a first yieldable means interposed between saidlever and said valve, and by a second yieldable means biasing said valvein a direction away from said annular valve seat.

9. A fluid pressure operated valve device, as claimed in claim 5,further characterized in that said carriage member is movably supportedby a pair of parallel spacedapart rollers.

10. A fluid pressure operated valve device, as claimed in claim 5,further characterized in that said first chamber in said casing is opento atmosphere whereby said valve controls the rate of flow of fluid fromthe atmosphere to said second chamber accordingly as said valve is movedby said cam and lever toward and away from saidvalve seat as saidcarriage member is moved longitudinally in one direction or in anopposite direction in response to variations in pressure of fluid actingon said abutment.

References Cited UNITED STATES PATENTS 2,629,638 2/1953 Snyder 303 402,926,966 3/1960 Swander 30331 X DUANE A. REGER, Primary Examiner.

